"We tend to lose a bit of muscle over time as we become less active, so strength training keeps your muscles strong, which helps you get in and out of chairs and get up a hill."

Once you've started your strength regimen, the challenge is to keep progressing.

"The only way to build muscle is through progressive overload, meaning you put your body under a weight and progress that weight," Pia Therese, trainer and owner of MFW Fitness, tells Coach.

"Muscle grows when your body is under stress from the weight and it adapts by getting stronger. So if you keep using the same weight or keep using your body weight, it might [plateau]."

Pay a professional (if you can)

There's more to lifting weights than just doing repetitions. Technique makes all the difference to injury prevention, as well as how a movement feels and how well you progress, so Therese says it's a good idea to start under the watchful eye of a professional – even if you just have a few sessions with a trainer to nail your technique.

"There is an element of risk when you're putting your body under a load so it's probably best to start under the guidance of a personal trainer to show you the basics and teach you how to progressively move up in weight," she says.

"The trainer will be able to ensure you have correct technique and that you've not going too heavy or too light."

But if that's not in your budget, then Therese says some YouTube or Instagram tutorials can get you going.

Use your body weight

You don't have to fork out for a gym membership or even a set of dumbbells when you're getting started – your body weight is sitting there, begging to be used.

"Squatting is a big movement that uses a lot of muscles in the body, including the butt and thighs and your core," Therese explains. (Squats, and the other exercises here, are demonstrated in the video below.)

"I find that squatting brings about the biggest changes to your body composition, along with a healthy diet, of course. You can do them anywhere, any time – even if you squat in the kitchen while you are waiting for your food in the microwave."

For your upper body, you could do tricep dips on the bench or couch.

"Push-ups on the floor are another good one and you can eventually challenge yourself by putting your hands on the floor and elevating your feet on the couch."

But the challenge with using your body weight at home is keeping up the motivation to progress.

"You might be able to do 20 push-ups in a minute and then after a few weeks you end up being able to do 30 and the next week you do 40 and you keep progressing," Therese says.

Start on pin machines at the gym

If you're new to the gym, Therese says starting on pin machines — as opposed to free weights — is a good way to minimise your risk of injury.

"With free weights like dumb-bells, kettle bells and barbells, there is a bit more element of risk because your body is required to provide a lot of stability in order to move that weight around," she points out.

"But if you're doing it on a machine, you're a lot more supported."

If you can manage 10 to 15 repetitions of a movement without any strain or burn, then Therese suggests incrementally increasing the weight until you can do eight to 10 repetitions to feel fatigued.

"Once you've worked that out, you would do two warm-up rounds with 10 reps of a weight that's 50 to 75 percent of your maximum with a minute rest in between," she says.

"Then do two sets of eight or nine or 10 repetitions at your maximum before moving to the next exercise. You'll improve quite quickly and before long will find that your 90 percent resistance is now your warm-up."

"Tell yourself that you're going to get stronger if you don't quit. If you were finding it easy, then you're not challenging yourself enough."

That said, if you are feeling pain or a popping sensation then you need to stop.

"If your knees are hurting when you're doing a squat or lunge, it means that your knee is copping the weight of the load, rather than the quads, calves and butt – your knees shouldn't hurt," Therese says.

"You might need to reassess your technique. Often people with poor technique find it doesn't hurt at the start but gradually starts to hurt because they've been doing an incorrect movement over time."